Wobble plate engines have been known for many years. Early engines of this type comprised a number of parallel pistons disposed about a central driven shaft. Lateral displacement of the pistons is transformed to rotational motion of the shaft by a wobble or smash plate fixed at an angle on the shaft. Reciprocation of the piston causes a tangential displacement of the wobble plate thereby rotating the shaft.
Australian Patent number 14759/23 in the name of Crankless Engines (Aus.) Pty Ltd describes a dual swash-plate engine wherein the swash-plates are driven by double ended pistons sharing a common combustion chamber. This engine, and other engines developed by Crankless Engines (Aus.) Pty Ltd where incorporated in motor vehicles.
Although wobble plate engines have been known for 70 years they have not been generally accepted as internal combustion engines. The use has been limited to hydraulic pumps and other driven devices as opposed to driving devices. Various attempts have been made to improve or modify the basic wobble plate design for use in internal combustion engines.
Australian Patent Application number 41322/85 in the name of S.V. Engine Co. Pty Ltd described a number of improvements that could be made to the design of a wobble plate engine. These included a damping system for stabilization; a balancing arrangement; a linkage arrangement enabling variation in the tilt of the wobble plate; and improved overall construction features.
Reference may also be made to United Kingdom Patent number 2101226 in the name of Star Motors which describes a high pressure vapour driven engine based on a swash plate. The cylinders are arranged around a central power shaft in conventional manner. The swash-plate is rotatably mounted on the shaft and is connected to the pistons by connecting rods incorporating ball joints at each end. The engine is designed to be driven by high pressure steam derived from geothermal or solar energy.
Despite the many years of development the wobble plate engine has failed to be accepted for internal combustion engine manufacture. This is because of vested interests in cranked engines and because of fundamental design problems. One such design problem is the direct load placed on the wobble plate by the pistons when they fire. The line of action of the pistons is parallel to the axis of rotation of the wobble plate, thus there is a large component of force directed through the wobble plate. Only a portion of the applied force is directed along the wobble plate to force it to rotate. This results in high frictional loads and reduced efficiency of the motor.